High brain network system segregation is differentially linked with cognitive performance across the life span.
Level 4 - case-series / case-control
Cross-sectional observational neuroimaging study comparing two age cohorts.
PubMed 42039097 · doi:10.1162/NETN.a.542
What was done
Researchers analyzed resting-state fMRI and cognitive data from 179 younger adults (ages 18–29) and 117 older adults (ages 60–89). System segregation was quantified globally and across specific sub-networks using Schaefer's 7-network parcellation. The authors evaluated relationships between system segregation and performance across three cognitive domains: semantic memory, executive function, and episodic memory, testing for mediation effects and age-group differences.
What was found
The abstract reports directions without providing specific numerical values or effect sizes. Older adults exhibited a global reduction in system segregation compared to younger adults, particularly affecting the somatomotor, ventral attention, and frontoparietal networks. Global system segregation mediated the negative effect of older age on semantic and executive performance. In subgroup analyses, higher system segregation correlated with better semantic performance in both age cohorts, but correlated with better executive performance only among older adults.
Why it matters
The study suggests that functional brain network segregation becomes increasingly important for maintaining executive function in late adulthood, highlighting preserved network modularity as a potential marker of healthy cognitive aging.
Limits
The study is cross-sectional, comparing discrete young and older cohorts rather than tracking longitudinal trajectories over time. Middle-aged adults (ages 30–59) were excluded, leaving a gap across the middle lifespan. The abstract does not report numerical effect sizes, confidence intervals, or p-values.
Cited by
- supports The function and stability of the frontoparietal brain network, which is critical for focus and attention, decreases with age.